“The Channel stopped you, but not us,” read a slogan jokingly repeated by men of the British 6th Airlanding Brigade as they prepared to fly to Normandy on June 6th, 1944. They were just one small part of the largest air, sea, and land operation ever attempted in the history of warfare.

In the last phase of planning for D-Day, Allied commanders understood that air power would be critical. Before a single landing craft hit the beaches, they needed to set the stage from the air: win control of the skies, isolate the battlefield, and directly support the troops once ashore.

The air plan unfolded in three phases. First, during the preliminary phase, the top priority was to destroy the Luftwaffe and gain air superiority over Normandy. Second, in the preparatory phase, air forces were to isolate the landing area by destroying rail and road infrastructure, making it difficult for German reinforcements to reach the beaches. Finally, during the invasion itself, Allied aircraft would defend the beachhead from German air and naval forces and help the ground armies break out into France by attacking targets on and behind the front.

Understanding the geography of the landing area was crucial. In the months before the invasion, photo reconnaissance aircraft meticulously mapped every foot of the Normandy coastline and the countryside beyond. One of the key aircraft used for this was the de Havilland Mosquito. Nicknamed the “Wooden Wonder,” the Mosquito was one of the first truly multi-role combat aircraft. Although designed as a fast bomber, its speed and range made it ideal for reconnaissance. The PR (photo-reconnaissance) version carried multiple cameras and could exceed 400 mph.

Alongside this technical reconnaissance, the Allies turned to more creative methods. In 1942, the British government appealed to the public for photographs of the European continent. Families rifled through their holiday albums, and by the war’s end more than ten million postcards and photos had been sent to the Admiralty-run Inter-Services Topographical Department. These images helped refine maps and terrain models for the invasion.

But as land and sea plans were refined, the air strategy became a source of friction. At Eisenhower’s headquarters, SHAEF, the two Allied tactical air forces came under the command of Air Chief Marshal Sir Trafford Leigh-Mallory. The two strategic bomber forces, however—Carl Spaatz’s USAAF and Sir Arthur Harris’s RAF Bomber Command—were reluctant to subordinate themselves to him.

Since early 1943, under the Pointblank directive, they had been bombing Germany directly: the U.S. Eighth Air Force by day against industrial targets, and RAF Bomber Command by night against cities. Results against German output varied, but the campaign was beginning to have a devastating effect on the Luftwaffe. A major turning point came at the end of 1943 with the introduction of long-range fighter escorts. P-51 Mustangs equipped with Rolls-Royce Merlin engines could now accompany bombers deep into Germany. Crucially, fighter pilots were allowed to range ahead of the formations, sweeping the skies of German interceptors and attacking airfields and other targets of opportunity.

By early 1944, Allied planners sought to exploit this advantage in an intense offensive later known as “Big Week.” Between February 20th and 26th, 1944, USAAF bombers, supported by the RAF, attacked German aircraft production facilities. Big Week didn’t completely knock out the Luftwaffe, but it forced the dispersal of aircraft production and cost the fighter arm roughly 14% of its pilots.

Despite these successes, Spaatz and Harris did not want to divert bombers to invasion support. Spaatz especially believed that Germany could be defeated by strategic bombing alone, without risking a large-scale land invasion. But Operation Overlord was too important for their objections to stand. On April 14th, 1944, both strategic air forces were placed under the control of Eisenhower’s deputy, Air Chief Marshal Sir Arthur Tedder, at SHAEF. Only then did their target lists shift.

U.S. strategic air forces began focusing on Germany’s fuel production facilities. These raids were costly but contributed to severe fuel shortages in the Luftwaffe and destroyed still more German fighters. At the same time, British bombers moved from targeting German cities to hitting transportation nodes, supply depots, and positions in France. New target-marking techniques improved accuracy, and American bombers soon joined in, hitting French rail yards and bridges.

This “Transportation Plan” played a central role in disrupting German logistics and reinforcements. From February to June 1944, concentrated air attacks reduced German rail traffic in northern France by about 85%, making it extremely difficult to move troops and supplies toward Normandy. Interestingly, about two-thirds of the bombs were dropped away from the actual invasion area to mislead German intelligence. The deception worked. Hitler remained convinced as late as July 1944 that the main Allied invasion would come in the Pas-de-Calais region. This misjudgment helped keep German reinforcements away from Normandy.

The tactical air forces—U.S. Ninth Air Force and RAF Second Tactical Air Force under Leigh-Mallory—supported the strategic offensive by striking within a ring around Normandy. They attacked roads, bridges, and airfields to further isolate the sector. RAF Bomber Command also flew about 2,000 sorties to lay mines in the sea lanes flanking the invasion corridor and at the entrances to German-held ports. By June 6th, Normandy was thoroughly isolated from the rest of German-held Europe by air and sea.

By then, the Allies had almost complete control of the air. Between January and June 1944, they had effectively smashed the Luftwaffe in Western Europe. Many German fighter units had been stripped from France and Belgium and sent back to defend the Reich itself. Those that remained in the West could offer only token resistance when Overlord began.

In the hours before the landings, a huge aerial deception effort was launched across the Channel under the umbrella of Operation Bodyguard. The aim was to draw German attention away from Normandy. On the night of June 5th, Lancasters from No. 617 Squadron—the “Dam Busters”—dropped clouds of metal strips, code-named “Window,” near Le Havre. The bombers flew carefully planned circular patterns to make the radar echoes move at speeds and in directions that looked like a fleet. The Germans took the bait, mistaking the radar returns for invasion convoys and diverting defenses away from the real beaches. Other aircraft carried electronic jammers to disrupt German radar, adding another layer of confusion.

Behind this deception screen lay a huge Allied air armada—over 11,000 aircraft of all types, all marked with black and white “invasion stripes” to reduce friendly fire incidents. Those stripes, born of bitter experience in Sicily, were ordered only on June 3rd and hastily painted on many aircraft just hours before takeoff.

The very first Allied troops into France would be paratroopers. British 6th Airborne and American 82nd and 101st Airborne divisions were tasked with seizing key bridges, road junctions, and flanks behind the beaches. For many of these men, it was their first combat.

The Douglas C-47 Skytrain—known as the Dakota in RAF service—became one of the symbols of D-Day. Rugged and reliable, the C-47 could haul jeeps, light trucks, supplies, or about 28 fully equipped paratroopers on metal bench seats. Each paratrooper clipped into a static line that automatically opened his parachute when he exited the aircraft. C-47s also towed British Horsa gliders carrying anti-tank guns, artillery, and other crucial equipment.

More than 50,000 paratroopers were delivered by C-47s in the first days of the Normandy campaign. Many missed their intended drop zones due to clouds, flak, and navigational errors. Some were scattered miles from their objectives; some drowned in flooded marshes. One famous example was Private John Steele of the 82nd Airborne, who became entangled on the church steeple in Sainte-Mère-Église and hung there for hours while the battle raged below. Despite the chaos, these airborne forces managed to secure many of their key objectives.

Next came the heavy and medium bombers, tasked with hitting coastal batteries and beach defenses. To preserve secrecy, concentrated bombing of the invasion area was delayed until the last hours before H-Hour. In the very early morning of June 6th, more than 1,000 RAF Lancasters and Halifaxes dropped over 5,000 tons of bombs on ten German coastal batteries, while a similar number of U.S. B-17s and B-24s struck beach defenses.

But a combination of low cloud and fears of hitting Allied troops led many crews to delay release—dropping too far inland. Most British bombs fell beyond the bunkers they were intended to destroy, leaving Allied warships to duel with coastal guns during the day. On the American sector, particularly on Omaha, bombing had little effect on the German defenses despite almost 3,000 tons of ordnance dropped. Only at Utah Beach, where B-26 Marauders attacked from lower altitudes, did the air attack significantly weaken German positions.

Even so, with naval gunfire and determined infantry assaults, most coastal defenses were gradually silenced. By evening, 156,000 Allied troops were ashore. Airborne reinforcements, including the glider-borne 6th Airlanding Brigade, continued to arrive. The first day’s objectives were not all achieved, but a foothold had been secured. One glaring question remained: where was the Luftwaffe?

On D-Day itself, the Luftwaffe response was minimal. German aircraft flew only a few hundred sorties compared to the Allies’ roughly 14,000. The German plan had been to throw large numbers of aircraft into the battle from Germany once the invasion was confirmed. A week after D-Day, they tried. Air units surged forward and mounted major attacks—but the cost was staggering. Even if German losses were sometimes lower in absolute numbers than Allied losses, they were proportionately devastating. German squadrons could not replace crews or machines as quickly as the Allies. Fighter formations were shredded.

With the Luftwaffe unable to contest the skies, Allied tactical air forces turned increasingly to attacking ground targets. Armed with bombs, rockets, and sometimes napalm, P-47 Thunderbolts of units like the 78th Fighter Group flew low-level missions from bases in England and, later, Normandy. They attacked anything that moved on the narrow French roads: vehicles, rail traffic, convoys.

These attacks were not one-sided. On June 10th, 1944, ten P-47s of the 78th were shot down in a single bombing mission after being bounced by about twenty German fighters. But overall, the air balance remained overwhelmingly in the Allies’ favor.

Another key ground-attack aircraft was the Hawker Typhoon of the RAF Second Tactical Air Force. Originally designed as a high-performance interceptor, it evolved into a formidable low-level strike fighter. With a powerful engine and heavy armament of cannons, bombs, and rockets, the Typhoon gained a fearsome reputation as a tank killer, though postwar analysis showed that reported tank kills were often exaggerated. What is certain is that Typhoons and P-47s devastated German trucks, supply columns, and soft-skinned vehicles—the lifeblood of armored formations. Destroying logistics delayed or disrupted German counterattacks against the British and Canadians.

The cost was high. During the Normandy campaign, 151 Typhoon pilots were killed in action—about 22% of those who flew in the theater.

The impact of air superiority on German ground operations is well illustrated by a report from Field Marshal Erwin Rommel dated June 12th, 1944: “The enemy has complete command of the air over the battle zone and up to about 100 kilometers behind the front and cuts off by day almost all traffic on roads or by-ways or in open country… Manoeuvre by our troops on the field of battle in daylight is thus almost entirely prevented, while the enemy can operate freely… Neither flak nor the Luftwaffe seems capable of putting a stop to this crippling and destructive operation of the enemy’s aircraft.”

Unable to destroy the beachhead, German forces tried to contain it, relying on the difficult bocage terrain to offset Allied advantages. But when the ground battle bogged down, the Allies used bombers to break stalemates. The bombardment of Normandy continued through June and July. In early July, RAF heavy bombers carpet-bombed Caen, leaving much of the city in ruins. On July 24th, the U.S. Army launched Operation Cobra near Saint-Lô. Approximately 1,500 B-17s and B-24s dropped nearly 3,300 tons of bombs in an hour on German positions.

Lieutenant General Fritz Bayerlein, a German panzer division commander, described his front line afterward: “My front lines looked like a landscape of the moon, and at least seventy percent of personnel were out of action—dead, wounded, crazed, or numb.” It was one of the first major uses of the U.S. Eighth Air Force directly in support of ground troops. Some bombs went astray, tragically killing around 100 American soldiers and wounding about 500. Worse still were the civilian casualties. Le Havre, Caen, Rouen, Saint-Lô, Falaise—all suffered massive destruction. Roughly 300,000 Normandy civilians were left homeless, and nearly 20,000 died during Operation Overlord, most from Allied bombing.

Despite the horrific human cost, the combined effect of air power helped crack German lines. In August, the Allies finally broke out of the Normandy bridgehead. German attempts to build a new defensive line failed under relentless air attack, artillery, and ground pressure.

The Luftwaffe, already weakened before D-Day, was by then effectively broken in the West. It would never again contest Allied air superiority over Europe in any meaningful way. The battles ahead—in France, the Low Countries, and Germany—would be long and costly, but the outcome was now clear. With Allied armies advancing under skies they controlled, and German forces fighting under skies they no longer owned, defeat for Nazi Germany had become inevitable.